Taylor R Campbell wrote:
(I'ld even live with ($ a b c), but I can't seem to get that working either.) Try (define-syntax $ (syntax-rules () (($ x) (quasiquote x)))),
*** ERROR IN (console)@1.32 -- Ill-formed expression
(define-macro ($ x) (list 'quasiquote x)).
This seems fine, but...
($ a b ,(+ 3 2) c) *** ERROR IN (console)@6,1 -- Ill-formed special form: $
(This is subtly different from what I am guessing you asked for, but more general: I am guessing that by ($ a b c) you meant `(a b c), but in that case you have no way to write `a for something that is not a list (e.g., a vector). This may not matter to you -- modifying the above macros to do that is left as a trivial exercise for the reader.)
Oh, wait: ($ (a b ,(+ 1 2) c)) (a b 3 c) Okay, that's cool. Just to check, would the modification be: (define-macro ($ . x) (cons 'quasiquote x)) ? Nope. *** ERROR IN (console)@10.1 -- Ill-formed special form: quasiquote
I'll play around with that some more.
Alteration of the $ character in the readtable is generally a bad idea, because there may be many legitimate symbols that begin with it, which you would be left with no way to name.
I'm open for suggestions for other characters. € perhaps?
Alternatively, is there really no way for you to enter a backtick, or to translate the $ key stroke to a ` character? If you used $, your code would be very confusing for anyone who tried to read it.
Yeah, there really isn't. I expect my macro code to be a little confusing, but since I'm only going to be programming throw-away scripts on the device, I'm hoping it won't really affect anyone.
Alex Shinn wrote:
Blake> Hello everyone, I'm using Gambit on an iPod Touch, and have Blake> run into a small hitch when trying to write a macro. The Blake> hitch is that I have no way of typing in a ` on the device. Blake> It's just not on the keyboard.That's funny... ` is the only printable ASCII character it lacks. It has the pound, euro and yen signs, and several international keyboards, and no possible way to input `.
Yeah, go figure, eh? It's like they're trying to drive everyone to Python (or just away from APL ;).
But, how can you possibly code on that thing anyway? Apart from the pain of the horrid keyboard, there's the fact that you have no editor support. I would just ssh in from a real terminal, or cross-compile.
Ya know, I'm getting used to the keyboard quicker than I thought I would, and I've got vi on it, and there's a graphical editor, as well. When I'm at my desk at work, or at home, I do ssh in, but when my wife and I are watching TV (which doubles as the computer monitor), or when I'm on the subway, it's nice to be able to still hack.
And finally, Marc Feeley wrote:
Beware, fiddling with Gambit's internal routines will void the warranty...
Heh. I think I've already done that by porting it to the iPhone in the first place. :)
(begin
(##readtable-char-class-set! (current-readtable) #\$ ;; the character to dispatch on #t ;; this character is a delimiter (lambda (re c) (##read-quotation re #\`))) ;; handler #f)$(1 ,(+ 2 3) 4)
(1 5 4)
I just tried to type this in on the device, but it seems to have a ` in the middle of it. :P On the plus side, I ssh-ed in, and saved that as .gambcini and then, on the device,
$(1 ,(+ 2 3) 4)
(1 5 4)
Sweetness!
Thank you all for your help, Blake.